package com.chengdu.chun.util;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

public class MD5Utils {
    /**
     * MD5一次加密，容易被破解
     * @param plainText
     * @return
     */
    public static String stringToMD5(String plainText) {
        byte[] secretBytes = null;
        try {
            secretBytes = MessageDigest.getInstance("md5").digest(
                    plainText.getBytes());
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException("没有这个md5算法！");
        }
        String md5code = new BigInteger(1, secretBytes).toString(16);
        for (int i = 0; i < 32 - md5code.length(); i++) {
            md5code = "0" + md5code;
        }
        return md5code;
    }

    /**
     * 二次加密，附加我们自己的特殊字符串，破解很难
     * @param plainText
     * @return
     */
    public static String reMD5(String plainText){
        String sss = stringToMD5(plainText);
        return stringToMD5(sss.replaceAll("e", "csist").substring(3, 30));
    }
}
